Hi! Probably you're using the old 1.5.x versions of JBoss AOP, correct? This shouldn't be happening in the new version of JBoss AOP, since we added error messages to avoid invalid advice signatures. Regarding the inconsistency of class object creation vs. reflection creation, I believe that, if you try to invoke the code your aspect is intercepting (i.e., not the constructor of the aspectized class, but the real intercepted joinpoint), you will get an error, right? In this case, the error happens in different points due to the way the jvm handles the different ways of constructing the object. After all, if the advice signature is invalid, the code JBoss AOP generates is inconsistent regardless the way you call the constructor. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4115394#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...